Two pairs of invaginations of B the skin, which originally are called the prostomial and metastomial disks, grow round the intestine, finally fuse together, and form the skin and mus- cular body-wall of the future Nemertine, which afterwards becomes ciliated, frees itself from the pilidium investment and develops into the adult worm without further metamorphosis.
Mus.), E., 138 (14), 122 (12), 118 (40), 119 (18).
Rats and mice, especially the guayabita (Musmusculus), an extremely destructive rodent, are very abundant.
MOUSE, in its original sense probably the name of the semidomesticated house-mouse (Musmusculus), the type of the genus Mus and of the family Muridae.
Zoologically, there is no distinction between mice and rats; these names being employed respectively for most or all of the smaller and larger "mouselike" and "rat-like" representatives of the Muridae, whether they belong to the genus Mus or not.